The present invention relates generally to thermostats used for heating and cooling systems, such as gas or electric forced air furnaces, gas or electric radiant heating furnaces, electric forced air air-conditioning systems, and electric heat pumps.
One conventional thermostat sold by Home Depot of Atlanta, Ga. as the RiteTemp® 6020Z controls the furnace/air-conditioner (HVAC) using a low power radio transmitter. In addition, this thermostat can be used in a system to receive information from and provide signals to other devices such as alarm systems, outside lighting, etc. A similar system having additional features and capabilities is disclosed in U.S. Patent publication number US 2006/0196953. Another example of a radio thermostat is shown in US patent publication US 2008/0185451. The disclosures of these patent publications are incorporated by reference.
During peak power demands a power company needs to have users on the power grid cut back on power consumption to avoid blackouts. One known way to do this is to send a signal to a specially designed power meter that a power-save state exists. The power meter receives the power-save signal and instructs the air-conditioner to increase the target temperature without delay by, for example, 4° F., the power-save state. In exchange for permitting the power company to have such temporary control, the user will typically receive power at a reduced rate structure. Thermostats are often linked to other devices and systems by wireless connections. These thermostats, often called communicating thermostats, are typically used to communicate with the heating and cooling systems, remote controllers, or devices for controlling air flow through different parts of the building. Some communicating thermostats communicate with the power company through the power meter to, for example, provide some level of control to the power company during energy emergencies.